"If we were to pursue the idea to its logical conclusion, we would have to assume that every thought, every feeling, every sensation is somehow connected with an elementary process in the brain, with a…"

"Quantum mechanics has taught us that the world is not as solid and substantial as we thought."

"If you ask a theoretical physicist today, ‘What is an electron?’ he will probably say, ‘It is a symbol in the wave equation.’ We have got so far from the concrete picture of nature."

"Even if I should be right in this, I do not know whether my way of approach is really the best and simplest. But, in short, it was mine."

"The quantum theory is an 'unpleasant' theory, which I should have liked to assume to be true only if I were forced to do so by the facts."